This invention relates to current sensor assemblies of planar form arranged for connection in series with an electrical circuit, the assembly including a first conductive member adapted to contact a first conductor in the circuit, a second conductive member adapted to contact a second conductor in the circuit, a third member of conductive material connected at one end to the first conductive member and at its other end to the second conductive member such that current flow in the circuit between the first and second conductors is via the third member, third member being arranged so that the temperature rise at different parts of the member caused by current flow through the layer is different, the assembly including a plurality of temperature sensors located to sense the temperature of the third member at the different parts, and the assembly providing an output representative of current from the outputs of the temperature sensors.
There are many applications where it is desirable to monitor current in electrical equipment and systems. Knowledge of current and power consumption can enable power supply to be managed in the most effective way and can enable the detection of faults. Although current sensors are available, they are generally expensive and bulky. In FR-A-548895 there is described a current sensor having a self-supporting conductive strip extending between two terminals, the resistance of the strip being measured as its temperature changes under the effect of current flow.